Does anyone have advice on where or how to hire a business development professional?

We are a creative marketing agency that specializes in explainer videos and marketing animations. At this point, most of our new clients find us through our online advertising, however, they tend to be small to medium size businesses. Ideally we would like to start targeting larger companies, and are considering hiring someone to handle business development. However, we really need someone with existing connections who is willing to work largely on commission. This seems like an impossible combination. So the question is, where can we find someone to help with our business development who has the experience we need, but is also reasonably affordable? Are there other options we are missing? Thanks! Micah